Systems are known that utilize chips to receive a sample for optical inspection to determine whether an agent is present in the sample. The agents often include polymers, such as nucleic acids with detachably labeled probes bound thereto in a particular manner. The sample is passed through a detection zone where an excitation signal illuminates the probe. The labels of the probe are excited when present in the detection zone and emit an emission signal. The emission signal is received by a collector that is separate from the chip and that, in turn, directs the emission signal to a detector as a portion of a detection signal. The characteristics of the emission signal relative to the sample, the excitation signal, the surroundings, and/or other characteristics are then used by the system to detect the presence of the polymer and/or to analyze structure of the polymer.
Alignment between optical components and chips of prior art systems can be critical to the reliability of the system and the quality of information produced by the system. Emitters and/or collectors are often required to be focused into a small detection zone so that the position of a probe associated with a polymer can be determined with precision when present in the detection zone. Expensive, adjustable focus lenses are used in prior art systems to accommodate variations in the positional relationship between a chip used by the system and optical components that are separate from the chip. Costly motion control systems are also used in prior art systems to maintain the positional relationship between optical components and/or to minimize the impact of movement, such as vibrations in the system. There exists a need in the art for a system that minimizes the costs associated with positioning a chip relative to optical detection components and is less (if at all) sensitive to vibrations.
Prior art detection systems can have difficulty distinguishing emission signals from noise and/or disturbances within the system. This may be the case particularly in systems that attempt to detect a single polymer or molecule. Noise and/or disturbances may emanate from any number of sources, including emission signals that are overlapped with excitation signals in the system prior to being received by a detector. To this end, there also exists a need for detection and analysis systems that minimize or prevent the overlap of emission and excitation signals. There is also a need to increase the proportion of a signal received from each agent relative to background noise, transmitted illumination, and/or path fluorescence, particularly for single molecule detection. Compound lenses with relatively high numerical apertures are used in prior art systems to increase the proportion of signals received from any given agent. However, such compound lenses are often expensive and require significant amounts of space within a system. This prevents such high numerical aperture lenses from being incorporated in many detection systems, particularly where multiple detection zones are desired. Consequently, there is a need in the art for high numerical lens capable of being incorporated into a system with smaller spatial requirements and at a lower cost.
Expensive and space consuming lenses preclude the utilization of multiple detection zones on a single chip in prior art systems. In this regard, the amount of information that can be obtained from a sample in a given amount of time (i.e., throughput) can be limited in prior art systems. There is a need to reduce the cost and size of optical components in detection systems such that higher throughput, parallel processing of samples on a chip can be achieved in a cost effective manner.